Background: Elephantorrhiza elephantina
(Ee) and Pentanisia prunelloides
) are two medicinal plants which are widely used to
remedy various ailments including diarrhoea, dysentery, inflammation, fever, rheumatism, heartburn, tuberculosis, haemorrhoids, skin diseases,
perforated peptic ulcers and sore joints in southern Africa (South Africa, Swaziland, Botswana and Zimbabwe). The following study was
conducted to explore the in vitro
cytotoxicity, antioxidant properties and phytochemical profile of the two medicinal plants.
Materials and Methods:
The cytotoxicity of the aqueous and methanol extracts and fractions of both species was studied using the brine shrimp
lethality tests (BST) for the first time.
The results demonstrated that the lethality (LC50
) for crude extracts for both plants ranged between 1.8 and 5.8 ppm and was relatively
greater than that for the methanol, ethyl acetate and chloroform fractions of the extracts which ranged between 2.1 ppm and 27 ppm. This
suggested that crude extracts were more potent than their respective fractions, further explaining that the different fractions of phytochemicals in
these plant species work jointly (in synergy) to exert their therapeutic efficacy. Both aqueous and methanol extracts of the two medicinal plants
demonstrated a high degree of antioxidant capacity against the DPPH radical with the Duh and Yen inhibition percentage ranging between 4.5%
and 72%. Phytochemical studies of the rhizome extracts showed that the major compounds present include flavonoids, tannins, anthocyanidins,
anthraquinones, triterpenoids (oleanolic acid), the steroidal saponin Diosgenin, the sugars, rhamnose, glucuronic acid, Arabinose and hexoses.
This is the first report of the detection and isolation of diosgenin and oleanolic acid from the rhizome extracts of Ee
structures were determined using spectroscopic/spectrometric techniques (1H NMR and 13C and LC-ESI-MS) and by comparison with literature